79 Merc 140 hp Tilt wont go down

[brdlynlsn]

Refirbished with new hoses after sitting for 5 years. Tilt motor lifted up 140 HP Outboard '79. Wont go down. No, sound nor action when down button is pushed. Repair manual vaguely troubleshoots it as a hydraulic problem. Any suggestions? How do I release the pressure and safely lower the motor manually? Down bleeder valve on ram did no good to remove. Stumped?

 

[Chris1956]

Re: 79 Merc 140 hp Tilt wont go down

The motor must run for the motor to tilt down. Check the voltage to the green wire on the motor. It should be +12V when the trim botom button is pushed. If none, jumper voltage to thegreen wire to run the motor.

if all else fails, you can open one of the large hydraulic lines on the trim pump base. Oil will spray out and the motor will come down. Don't forget to refill the pump.

 

[brdlynlsn]

Re: 79 Merc 140 hp Tilt wont go down

Jumpering the green runs the motor down, thanks.

Cleaned all the contacts. Still couldn't run it down without jumpering. Replaced the down Selenoid still couldn't run it down without jumpering.

Any additional suggestions?

 

[hkeiner]

Re: 79 Merc 140 hp Tilt wont go down

Seems that if the tilt works OK when jumping the solenoid, then the motor and tilt mechanism are OK and that the problem is likely with the circuit between the solenoid and the down button. While pressing the down button, use a multimeter to check for continuity where there should be continuity, check for 12v where there should be 12v, and check for ground where there should be ground. Your shop manual should contain a wiring diagram to show you what and where to check.